COMPOSITION IS IDENTITY. Megan B. Wallace

Transcription

1 COMPOSITION IS IDENTITY Megan B. Wallace A dissertation submitted to the faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Philosophy Chapel Hill 1999 Approved by: William G. Lycan Keith Simmons C. D. C. Reeve Dorit Bar-On John Roberts

2 1999 Megan B. Wallace ALL RIGHTS RESERVED ii

3 ABSTRACT Megan B. Wallace COMPOSITION IS IDENTITY (Under the direction of: William G. Lycan, Keith Simmons, C. D. C. Reeve, Dorit Bar-On, and John Roberts) Unrestricted Mereologists claim that whenever we have two things, x and y, there is a further thing, z, which is their mereological fusion. One complaint against unrestricted mereology is that its ontological costs are too high: for any two (nonoverlapping) things in our universe, the mereologist will claim that there is a third (its fusion). And once we add fusions, we can also add fusions of fusions, and so on. To escape the charge of ontological extravagance, many mereologists have insisted that their view is ontologically friendly. One way to do this is to advance Composition is Identity (CI), which claims that the fusion of x and y is not a third thing, distinct from x and y, but is identical to x and y. But, we might wonder, how could the fusion of x and y fail to be a third thing, distinct from x and y? Much of the current philosophical literature on mereology and composition is dedicate to criticisms of CI. In my dissertation, I proceed systematically, taking on the objections to CI one by one, showing how this view can be defended and plausibly developed. Common to most of these objections, I argue, is that they all fail to take into account two important resources available to the proponent of CI. First, many ignore the availability of a plural logic and language, complete with plural quantifiers, plural predicates, and (perhaps most importantly) a plural/singular hybrid identity predicate. Second, none of them considers what I call plural counting, whereby our counts of objects are not constrained by singular quantification and singular identity statements. I show how these two resources can bolster a strong defense of CI, securing that mereology is, after all, ontologically innocent. In addition, I show how CI has the advantage of providing elegant solutions to an array of problems in philosophy: perception puzzles, problems of prevention and causation, shadow puzzles, and Frankfurt puzzles about moral responsibility. I also introduce a metaphysics of objects that, together with CI, addresses modal worries, including issues concerning CI and merelogical essentialism. iii

4 To my Mom and Dad, for their unconditional love and support. iv

5 ACKNOWLEDGEMENTS I would like to thank my dissertation advisor, Keith Simmons, for all of his time, patience, helpful comments, advice, and for cracking the whip when needed. Without him, this dissertation never would have been completed. I would also like to thank the other committee members, Bill Lycan, Dorit Bar-On, David Reeve, and John Roberts, for taking the time to give me such helpful feedback on my work. Their collective input was invaluable. I would also like to thank Ted Sider for helpful comments, criticisms, and objections. It was Ted s class on abstract entities that led me to obsess over mereological sums, so I thank him for cultivating a passion that would lead to the pages that follow. My colleagues, Ted Parent and Jason Bowers, also helped tremendously, and deserve many thanks for reading several drafts, and several versions of several drafts, many times over. Ted Parent deserves special thanks for being my roommate for part of the writing of this thesis. We would often stay up late (over many bottles of wine), discussing the relationship between some bananas and their mereological fusion. Not many people would be so genuinely (and voluntarily) patient and engaged, and not many philosophers would either. His constant feedback was commendable, and is always valued and appreciated. I would also like to thank another colleague, Adam Sennet, for always being encouraging and supportive, and for providing prompt and helpful feedback on my work. His support and friendship is always (and will always be) cherished. Finally, I would like to thank my mental ballasts. First, to my family: my mom and dad, my brother, Joe, and my sisters, Jen and Deb. Their love and emotional support always keeps me grounded and happy, even when (especially when) I m holding myself captive in the ivory tower. Second, to my colleagues and running partners: Sarah Scott and Emily Kelahan. Being able to run and talk shop, or run and talk non-shop, or just to run, period, has proven to be the best therapy. Logging miles with both of them has kept me constantly motivated and (relatively) sane. Also, a dissertation begins to look meager in comparison to running 26.2 miles. Five times over. Thanks to Sarah for showing me that if you can run for hours and hours, you can write a silly little dissertation. Third, to Eddie Sanchez, who taught me the fine art of chillaxing. v

6 TABLE OF CONTENTS LIST OF FIGURES.x CHAPTER 1. PARTS AND WHOLES... 1 Motivation: Why worry about parthood... 1 Parthood: Composition and Mereology... 7 Composition... 7 Mereology... 8 Composition is Identity: Three Varieties Weak Composition Thesis (WCT)... 7 Strong Composition Thesis (SCT)... 7 Stronger Composition Thesis (RCT)... 7 A Quick Note About Nomenclature Rejecting WCT and RCT Rejecting WCT Rejecting RCT vi

7 A Few Quick Words About Methodology COUNTING AND CI: INTRODUCING PLURAL COUNTING Introduction Logic Book Counting vs. Plural Counting Logic Book Counting Plural Counting A Comparison: Plural Counting and Relative Counting Relative Counting Three Worries for Relative Counting First Worry: Defining sortalhood Second Worry: Logical Inferences Third Worry: Conceivability Lesson Learned Plural Counting (Again) Back to the Counting Objection FOUR ARGUMENTS AGAINST CI AND RESPONSES Introduction Four Common Arguments Against CI Argument 1: The Indiscernibility of Identicals vii

8 Argument 2: The Principle of Ontological Parsimony Argument 3: The Substitutivity of Co-referential Terms Argument 4: CI and is one of Defensive Strategy Plural Language Singular and Plural variables, constants and quantifiers Plural predicates, distributive and non-distributive predicates A singular/plural hybrid identity predicate An analysis of is one of A Review of Plural Counting Addressing the Four Arguments Responding to Argument Responding to Argument Responding to Argument Responding to Argument CONSTITUTION, LUMP THEORY, MEREOLOGICAL ESSENTIALISM AND THE MODAL OBJECTION Introduction: The Modal Objection and Constitution Composition and Constitution: Deflating the Difference Four Puzzles of (Material) Constitution viii

9 The Marriage Paradox Ship of Theseus Tib and Tibbles Goliath and Lumpl CI and Solving the Constitution Puzzles Does CI entail Mereological Essentialism? Embracing Mereological Essentialism: the Lump Theory Back to the Puzzles Back to the Modal Problem ADVANTAGES OF CI Introduction Some Taxonomy Four Puzzles Shadow Eclipse Prevention Perception Concluding Thoughts: Broader Applications and Overdetermination in General REFERENCES ix

10 LIST OF FIGURES FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE FIGURE x